/*  mbed Microcontroller Library
    Copyright (c) 2006-2013 ARM Limited

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/
#ifndef MBED_I2C_SLAVE_H
#define MBED_I2C_SLAVE_H

#include "platform.h"

#if DEVICE_I2CSLAVE

#include "i2c_api.h"

namespace mbed {

    /** An I2C Slave, used for communicating with an I2C Master device

        Example:
        @code
        // Simple I2C responder
        #include <mbed.h>

        I2CSlave slave(p9, p10);

        int main() {
           char buf[10];
           char msg[] = "Slave!";

           slave.address(0xA0);
           while (1) {
               int i = slave.receive();
               switch (i) {
                   case I2CSlave::ReadAddressed:
                       slave.write(msg, strlen(msg) + 1); // Includes null char
                       break;
                   case I2CSlave::WriteGeneral:
                       slave.read(buf, 10);
                       printf("Read G: %s\n", buf);
                       break;
                   case I2CSlave::WriteAddressed:
                       slave.read(buf, 10);
                       printf("Read A: %s\n", buf);
                       break;
               }
               for(int i = 0; i < 10; i++) buf[i] = 0;    // Clear buffer
           }
        }
        @endcode
    */
    class I2CSlave {

      public:
        enum RxStatus {
            NoData         = 0,
            ReadAddressed  = 1,
            WriteGeneral   = 2,
            WriteAddressed = 3
        };

        /** Create an I2C Slave interface, connected to the specified pins.

            @param sda I2C data line pin
            @param scl I2C clock line pin
        */
        I2CSlave(PinName sda, PinName scl);

        /** Set the frequency of the I2C interface

            @param hz The bus frequency in hertz
        */
        void frequency(int hz);

        /** Checks to see if this I2C Slave has been addressed.

            @returns
            A status indicating if the device has been addressed, and how
            - NoData            - the slave has not been addressed
            - ReadAddressed     - the master has requested a read from this slave
            - WriteAddressed    - the master is writing to this slave
            - WriteGeneral      - the master is writing to all slave
        */
        int receive(void);

        /** Read from an I2C master.

            @param data pointer to the byte array to read data in to
            @param length maximum number of bytes to read

            @returns
                 0 on success,
             non-0 otherwise
        */
        int read(char* data, int length);

        /** Read a single byte from an I2C master.

            @returns
              the byte read
        */
        int read(void);

        /** Write to an I2C master.

            @param data pointer to the byte array to be transmitted
            @param length the number of bytes to transmite

            @returns
                 0 on success,
             non-0 otherwise
        */
        int write(const char* data, int length);

        /** Write a single byte to an I2C master.

            @data the byte to write

            @returns
              '1' if an ACK was received,
              '0' otherwise
        */
        int write(int data);

        /** Sets the I2C slave address.

            @param address The address to set for the slave (ignoring the least
            signifcant bit). If set to 0, the slave will only respond to the
            general call address.
        */
        void address(int address);

        /** Reset the I2C slave back into the known ready receiving state.
        */
        void stop(void);

      protected:
        i2c_t _i2c;
    };

} // namespace mbed

#endif

#endif
